"To begin with, I learned much about rivers. In England a river is something easily comprehended. You can see along it, and across it, and it is locked, bolted and barred with towns and bridges and weirs and tow-paths. It is no more like an African river than a tame cat is like a leopard. Yet on the map the only difference is that perhaps the large river will have two mouths, and several tributaries running into it, exactly like a branch running into a tree. It wasn't like that at all. I had an atlas with me and when we reached the mouths of the great river I tried to find out where we were on the map. But it was hopeless. Where the map showed one channel there were hundreds on the chart. And the chart was out-of-date. It seemed a dream to me. I was under the impression that navigation nowadays was a humdrum affair of making points, steering on a ruled pencil line on the chart, so much for currents, so much for tides and so on. So it is, no doubt, in a great measure; but we can hardly realize how much of it is sheer skill and gallant daring. Even the men who do it don't realize it because they are always doing it. That first voyage to Port Duluth was a revelation to me in several ways. I had my own private troubles you may be sure. I was as green as grass. My hands blistered and my heart sickened many a time. But I am glad to think I could see other things as well. To me it was thrilling to look out across the oily blue glitter and see a hazy line which was the Ivory Coast. There was the Slave Coast and the Gold Coast--the words had a new significance now! And when I came up out of that awful engine-room and saw the land close in, the eternal grey-green line of mangrove swamp holding up the blazing vault of the sky, I forgot my troubles. I said to myself in a whisper, 'This is what I came for. This is the world!'